1. Field of the Invention
The invention relates generally to an option function test apparatus for a semiconductor memory device, and more particularly to an option function test apparatus for a semiconductor memory device which can test previously on-chip functions in a state of a wafer before when the functions are classified into each device' specifications, upon mass-production of the functions each mounted according to each device' specification.
2. Description of the Prior Art
Generally, an asynchronous memory device can be classified into an extended data output(EDO) mode, a fast page(FP) mode and a self refresh mode, wherein a function selector is used to discriminate the operation modes.
However, as the conventional semiconductor memory device cannot test previously all the functions already mounted, in a state of a wafer, before a process is proceeded according to the specification of a set operation mode, it usually employs fuse option or metal option, or bonding option etc. to selectively test the functions. However, in case of bonding option, though the conventional method can easily test the functions using the already-mounted multifunction check, there is a problem that it has to perform a bonding for selecting the specification before the testing, thus requiring an additional cost. The additional cost may include the cost related to lead frame or assembly.
Also, in case of fuse option, though the conventional method can easily test the functions using the already-mounted multifunction check, there is a problem that it has to perform a fuse blowing for selecting the specification before the testing, thus requiring an additional cost.
Similarly, in case of metal option, though the conventional method can easily test the functions using the already-mounted multifunction check, there is a problem that it requires an additional mask manufacturing for selecting the specification before the testing.